The present invention relates generally to analysis of patient specific medical history and laboratory results, and more particularly to computer-implemented methods and products for assessing a patient's medical risks and formulating a treatment strategy.
Coronary heart disease is the leading cause of morbidity and mortality in the United States, accounting for approximately 500,000 deaths per year, and an associated annual morbidity cost of more than $200 billion. Over the past several decades, numerous clinical and epidemiological studies have shown that an elevated blood cholesterol level is one of the major modifiable risk factors associated with the development of coronary heart disease. These studies have demonstrated that low-density lipoprotein (LDL) cholesterol is a primary lipoprotein mediating atheroscelorsis. Cigarette smoking, hypertension, diabetes, and a low level of high-density lipoprotein (HDL) cholesterol are other risk factors that have been implicated in coronary heart disease.
The National Institutes of Health established the National Cholesterol Education program in 1985. The National Cholesterol Education Program Adult Treatment Panel I (NCEP-ATP I) developed its first set of guidelines in 1988. The guidelines establish clear goals for patients with lipid abnormalities. Revised guidelines were developed in 1993 (NCEP-ATP II) and in 2001 (NCEP-ATP III). Risk stratification continues to determine LDL goals and the intensity of LDL-lowering therapy. Dietary therapy remains the first line of treatment with drug therapy reserved for use in patents at high risk for coronary heart disease or patients who do not respond to non-pharmacological therapy.
Under the current guidelines, optimal cholesterol screening now includes a lipoprotein profile, preferably using blood drawn in a fasting state. The lipoprotein profile includes total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides. The lipoprotein profile cannot be interpreted without knowledge of the patient's risk factors. The major risk factors that modify low-density lipoprotein goals include age (men over 45, women over 55 having normal onset menopause), smoking status (current tobacco user or within the last 5 years), hypertension (blood pressure exceeding 140/90 mmHg), high-density lipoprotein levels, and family history of coronary artery disease. Patients with diabetes and those with a ten year cardiac event risk of 20% or greater are considered coronary heart disease equivalents. An additional step in the determination of coronary heart disease risk involves the calculation of the Framingham risk score (FRS) for persons with two or more risk factors. The ATP III Guidelines also raise the threshold of low HDL cholesterol from less than 35 mg/dL to less than 40 mg/dL. An HDL level of 60 mg/dL or higher is considered to be a negative risk factor.
The FRS is a risk assessment tool that has been derived from data collected in the Framingham heart study. The ATP III Guidelines recommend that patients with two or more risk factors have their FRS calculated. The FRS consist of points that are allocated based on various degrees of risk associated with five categories: age, total cholesterol level, HDL cholesterol level, tobacco smoking status and hypertension and whether this condition is treated. The FRS point total results in a percent risk of having a cardiac event in the next ten years.
In the ATP III Guidelines, the target LDL level for patients with established coronary heart disease is still 100 mg/dL or less. Patients with diabetes and patients with an FRS of 20% or higher are considered coronary heart disease equivalents. Since patients with diabetes and patients with an FRS of 20% or higher are in the same risk category as coronary heart disease patients, it is recommended that they maintain an LDL level of 100 mg/dL.
The extent of LDL lowering therapy depends on the patient's coronary heart disease risk. The two major modalities for lowing the LDL level advocated by the ATP III Guidelines are therapeutic lifestyle changes and drug therapy. Patients are classified in one of three categories of risk: (1) coronary heart disease (CHD) and CHD equivalents, (2) two or more risk factors, or (3) zero or one risk factors. The two or more risk factors category can be further subdivided into patients having an FRS score 12 or higher and patients having an FRS score less than 12.
Therapeutic lifestyle changes encompass diet, physical activity and weight loss. The ATP III Guidelines continue to stress the importance of non-pharmacological treatment, but recognize its limitations by reducing the trial of these modalities from six months to twelve weeks before considering the use of medications to assist in achieving recommended LDL goals.
The failure of therapeutic lifestyle changes to modify LDL cholesterol levels or the presence of high CHD risk levels warrants the use of drug therapy. Several drugs have specific effects on lipoprotein metabolism, including bile acid sequestrants (resins), fibric acids, nicotinic acid, and statins. Bile acid sequestrants include cholestyramine, colestipol, and colesevelam. Fibric acids include gemfibrozil and fenofibrate. Nicotinic acid includes extended-release nicotinic acid (Niaspan) and sustained release nicotinic acids. The statins include lovastatin (Levitor), pravastatin (Pravachol), fluvastatin (Lescol), atorvastatin (Mevacor), synvastatin (Zorcor) and rosuvastatin (Crestor). If the LDL goal based on established risk is not achieved, therapy should be intensified with an increase in drug dosage or the addition of another LDL-lowering drug.
The ATP III Guidelines recognized the increasing number of studies correlating elevated triglyceride levels with increased coronary artery disease risk. The ATP III Guidelines lowered the acceptable triglyceride level from the ATP II Guidelines. The primary modes of treating hypertriglyceridemia are diet and exercise. If indicated, nicotinic acid and fibric acid derivatives are the most effective drugs in lowering triglyceride levels. Triglyceride reduction is also a secondary benefit of statins.
Niapsan is one of only two products in the United States approved for increasing HDL levels. Low HDL cholesterol levels have been shown to be one of the highest risk factors contributing to coronary heart disease. Most of the drugs for treating cholesterol problems are designed to reduce LDL levels. Niaspan's active ingredient, niacin, is most effective in elevating HDL levels. The increase in HDL has been shown to significantly reduce the chances of coronary heart disease.
Statins work by slowing down the liver's production of cholesterol, high levels of which are implicated in atheroschelorsis, a disease process that leads to clogging of the arteries. Heart attack patients typically are given one of the FDA-approved statins at the time of discharge or within months of discharge from the hospital as a preventative measure against future heart attacks. Because of their effectiveness as a class for reducing LDL cholesterol and their favorable safety profile, statins are by far the most frequently used drugs as first line therapy for patients with high LDL cholesterol. Statins generally raise HDL cholesterol levels and lower plasmatriglycerides.
Three bile acid-binding sequestrants are currently available in the United States: cholestyramine (Questran), colestipol (Colestid), and colesevelan hydrochloride (Welchol). These resins significantly decrease LDL cholesterol and can produce small increases in HDL cholesterol. Bile acid sequestrants should generally not be used in patients with triglyceride levels above 200 mg/dL, and should not even be considered for use in patients with triglyceride levels exceeding 400 mg/dL.
Fibrates that are currently available in the United States include gemfibrozil (Lopid) and fenofibrate (TriCor). Gemfibrozil and fenofibrate can decrease triglyceride levels, increase HDL cholesterol levels and shift small, dense LDL particles toward larger, more buoyant sizes, improving and potentially correcting the lipoprotein abnormalities commonly found in Type II diabetes. Since neither fibrate drug adversely affects glycemic control, either can by used in patients with diabetes.
There is a need for a computer-implemented method and computer program product that can enable a physician to quickly assimilate all the pertinent medical data and guidelines recommendations necessary to evaluate a patient's medical risk for cardiovascular disease and determine a patient care management program that is best suited for an individual patient.